Corpse explosion deserves whatever people feel it's worth. Since
I'm not a poison or bone hybrid, I had enough skillpoints to max CE, and at lvl 28 it covers a respectable area
As for the golem... I can only give the you the view of someone who's using clay: clay can be cast anywhere, without an item. So it can be used for crowd control, and to take some heat off your skellies if a fanatism extra strong pack shows up. Or place it between your skellies and those archers. Or whatever. Monsters love the clay golem; they tend to go where he is.
Essentially, the golem is your only castable minion --- point and cast. Iron doesn't do that, so it's just another stupid minion, brainlessly attacking the closest enemy. I feel that I already have enough minions of this type; I don't need another one.
Also, the slow effect is not to be underestimated --- if you've ever seen an act boss slowed by clay, decrep and cold magi, you might agree

I also see it when I kill Pindleskin: when I enter the building, I cast my clay golem ahead to stop the group. He takes some beating, but usually doesn't even die (which wouldn't matter, since if he does I can just recast him) because the zombies are all slowed down...
I often have to recast him once or twice vs. Lister and his friends, mostly because I cast him right in the middle of the pack, and I use amp on them, not decrep.
In any case, you DO have the iron golem as well if you are using revives, so you can try both. Golems aren't damage dealers, so maxing one is unusual at best.
EDIT: when looking at iron golem, I always look at what *I* can do with it. Insanely rich people can make iron golems from things like IK mauls to get crushing blow, or use other godly items to make a minion with properties that the skellies just don't have. Since the golem WILL get lost eventually, this is definitely no option for me
